The present invention relates to a locking apparatus, in particular a locking apparatus with safety function, the subject of which is a so-called pushxe2x80x94push engagement mechanism that engages a moving body by a push operation and releases the engagement by a subsequent push operation, as well as a storage apparatus for vehicle.
Among locking apparatuses that comprise pushxe2x80x94push engagement mechanisms, there is one that is constituted by a cam part with heart-shaped cam groove provided on one of a moving body and a housing, and a swivel body that is provided on the other side and has a trace pin that moves on the inside of the cam groove. FIGS. 10(a)-10(c) show one of the conventional structures. In this example, a moving body in a housing, i.e. a storage tray, is moved against the force of forcing means toward the direction of symbol C to close an opening of the housing, and is moved toward the direction of symbol O by that force to become in the open state. The swivel body 100 having a leaf-shaped arm is attached to the housing inside the vehicle compartment so as to be able to move via a pivot 103, and it has a trace pin 102 on the tip. The cam part 104 is provided on the moving body, and it has a raised cam part 105 whose periphery forms a heart-shaped cam groove 106, and a guide groove 107.
The engagement operation of the pushxe2x80x94push engagement mechanism is as follows. FIG. 10(a) shows the engagement released state, where the moving body has moved in the direction of arrow O by the forcing means, and it is pulled out from the housing. In this open state, when the moving body is pushed back into the housing against the force of the forcing means toward the direction of arrow C in FIG. 10(a), the trace pin 102 first meets the engagement guide cam surface 107a of the guide groove 107, and the swivel body 100 rotates counter-clockwise. Upon further movement, after contacting the engagement guide cam groove 106a of the cam groove 106, the trace pin 102 collides with the stopper cam surface 104a at the front of the cam part. The moving body is pushed in up to that collision. When the pushing force is released, the moving body is pushed back by the force of the forcing means, and the trace pin 102 engages the engagement groove 106b of the cam groove 106 as in FIG. 10(b). The moving body is stopped by that engagement (that is, the push engagement operation is completed), and it is held in the housing.
In the next operation of the mechanism, when the moving body is pushed toward the direction of arrow C1 in FIG. 10(b), the trace pin 102 meets the stopper surface guide cam surface 104b at the front of the cam part, and is led from that guide cam surface 104b up to the neighboring stopper cam surface 104c accompanying the rotation of the swivel body 100. When the pushing force is released, the moving body is pushed toward the direction of arrow C in FIG. 10(a) by the force of the forcing means. As a result, the trace pin 102 returns from the stopper cam surface 104c to the original position through the contact of the cam groove 106, the guide cam groove 106c, the guide cam surface 107b on the side of the guide groove 17 along the way, and becomes in the open state.
From the fact that the above pushxe2x80x94push engagement mechanism is constituted by the swivel body 100 with the trace pin 102 and the cam part 104, as opposed to the type published in Japanese Utility Model publication No. H5-91964, in which a pair of engagement pieces engages and releases a tab of the other member, it is simpler as it does not require a dedicated spring member. Additionally, it is superior in terms of operating quality in that there is less noise when engaging and releasing. However, with this structure in FIG. 10(b) in which the moving body is engaged, when an abrupt load (this load is an unanticipated load that would make a small movement of the moving body toward the direction opposite to the force pressure of the forcing means and roll the swivel body 100) is applied, i.e. by a sudden stop or collision while driving, a condition identical to the push release operation can occur. If this happens, the trace pin 102 meets the guide cam surface 104b, and it easily moves from the stopper cam surface 104c to the releasing guide cam groove 106c of the cam groove 106 and the releasing guide cam surface 107b of the guide groove 17. It may cause an unanticipated and sudden engagement release.
These erroneous operations damage the performance and quality of the product. As countermeasures, for example, the shape of the engagement groove 106b is modified such that the groove is firmly engaged with the trace pin 102, or a setting the force pressure of the forcing means is adjusted. Nonetheless, the operating performance tends to be sacrificed, and it is still unsatisfactory. In the prior art, as in Japanese Patent Publication No. H7-266996, albeit using a different engagement mechanism, there is also known a structure that prevents in advance the occurrence of the unanticipated engagement release as above. However, the structure requires a spring member which forces the cam member on which the cam groove is formed to swivel one-way by the spring member. The larger number of parts is needed and it becomes more complicated. It is not also widely applicable as the force pressure setting of the spring member would be necessary for each product.
The object of the present invention is to solve the problems such as above. Specifically, it is an object of the invention to provide a pushxe2x80x94push engagement mechanism formed of a heart-shaped cam part and a swivel body, wherein the occurrence of unanticipated engagement release of the pushxe2x80x94push engagement mechanism can be prevented by a simple and widely usable structure.
Another object of the invention is to provide the pushxe2x80x94push engagement mechanism as stated above, wherein an improvement of the reliability of the locking apparatus can be achieved, and it will be able to further expand the uses of the locking apparatus to other kinds of storage apparatuses.
Further objects and advantages of the invention will be apparent from the following description of the invention.
In order to achieve the above-mentioned objects, a locking apparatus has a pushxe2x80x94push engagement mechanism and comprises a cam part with a heart-shaped cam groove provided on one of a moving body and a housing, and a swivel body provided on the other of the moving body and the housing and having a trace pin that moves on the cam groove, wherein the moving body is engaged with the housing at a fixed position by an operation of pushing the moving body opposite to the force of forcing means, and the engagement can be released by a subsequent push operation. Furthermore, the swivel body has a balancer that detects the load when an unanticipated load such as impact is received while in the engaged state, so as to make it possible to prevent the trace pin from moving from an engagement groove of the cam groove to a releasing guide cam groove.
In the present invention, xe2x80x9cwhen an unanticipated load such as impact is receivedxe2x80x9d means that when a vehicle is suddenly stopped while driving, a collision occurs, or excessive vibration is directly or indirectly received. In such cases, the moving body is slightly moved toward the direction opposite to the force of the forcing means and the swivel body moved. xe2x80x9cDetects the loadxe2x80x9d means that the swivel body receives the load and automatically or by itself tries to allow the trace pin to move from the engagement groove of the cam groove to the releasing guide cam groove. xe2x80x9cCam part with a heart-shaped cam groovexe2x80x9d means a type at least having a cam groove that is heart-shaped in the periphery of a raised cam part as the construction of the cam part.
The above structural characteristic is that, when the unanticipated load is received, the trace pin and the engagement groove shift positions relatively so as to release the engagement, but that shift of positions is corrected by the balance adjusting operation of the balancer of the swivel body, and the trace pin and the engagement groove are automatically moved toward engagement again, such that the releasing engagement is prevented. Accordingly, the storage apparatus for the vehicle according to this invention is particularly suitable for automobiles, trains, ships, airplanes, and so on, which tend to receive the sudden loads noted above, and the erroneous operation can be eliminated. Also, the manufacturing cost can be minimized, and the product operation, quality and safety can be improved.
In the first aspect of the invention, the swivel body comprises an attachment part for pivot that is attached on the side of the housing or moving body to be capable of swinging, a first arm, and a second arm. The first arm is connected to the attachment part from which the trace pin projects, and the second arm is connected to the attachment part at an angle of at least 90 degrees to the first arm to form the balancer. This materializes the present invention from the shape of the swivel body. Because this second arm is disposed at an angle of at least 90 degrees to the first arm in the engaged state, it is the optimal mode for controlling the direction of swinging of the swivel body and making it move (balance adjusting) exclusively not to disengage from the groove.
In the second aspect of the invention, the balancer comprises a spindle or weight that works in cooperation with the trace pin and the force of the forcing or urging means so as to return the swivel body which swings due to the load to the engagement groove. This spindle controls the rotational direction of the swivel body to the side of the engagement stopper cam surface. The urging means moves the moving body toward the direction of the engagement groove. The trace pin is moved by the movement of the moving body to the engagement groove and comes to the engaged state. The present invention utilizes this series of movements.
In the third aspect of the invention, the swivel body is a molded resin product, and the second arm has a metal member for the spindle on at least one part thereof. This is a superior structure in terms of producing a smaller weight for the spindle, because the swivel body in the present invention is used for balance adjustment operation. There may be a construction such that a metal member is inserted in the balancer, and the second arm itself is constituted by a metal member, and the like, and either is applicable to the present invention.